Once a drug has been repackaged, reconstituted or dispensed from its original stock bottle it must be assigned a beyond use date. The beyond use date is the last day and time the product is guaranteed to be stable, potent and safely used. This differs from the expiration date, in that the expiration date is the shelf life of the product from the manufacturer before it is prepared or dispensed from the original container.
In retail pharmacy, most solid medications such as pills have a BUD of one year from the time the drug is dispensed into a medication bottle. There are some exceptions, such as dabigatran (Pradaxa) which has a BUD of 4 months once the bottle is opened. Some drug stock bottles contain desiccants (a little packet which absorbs water) which protect the medication from moisture. Watch for these medications, as the desiccant is there for a reason, and it might be best to dispense the medication in the original stock bottle if appropriate. Medications that should be dispensed in the original bottle to preserve the integrity of the product include dabigatran, Creon and nitroglycerin.
Many refrigerated drugs are dispensed in the original packaging but have a beyond use date once the product is removed from the refrigerator and opened. Most insulins have a BUD of 14 or 28 days. Latanoprost, an ophthalmic solution that is refrigerated until opened, has a BUD of 6 weeks. Some patients like to receive a 90-day supply of latanoprost, so it’s important to note the product should be used within 6 weeks of being opened.
Non-sterile aqueous (water containing) products, such as reconstituted antibiotics, have a BUD of 14 days if refrigerated. Some reconstituted oral antibiotics do not require refrigeration. The label on the product to be reconstituted contains the recommended beyond use dating information along with how the drug should be stored.
DETERMINING BUD (beyond use dating)
The official resource for determining beyond use dates for non-sterile compounded products is USP chapter <795> and USP chapter <797> for sterile products (used mostly in hospital pharmacy). Beyond use dating is especially crucial for sterile injectable products and they have much shorter beyond use dates and times down to mere hours. Many products that are prepared in hospital pharmacy have beyond use dates and times of 12 to 48 hours depending on the medication, preparation and storage. Drugs prepared for home infusion may be shipped with a BUD of 48 hrs, a week, or two weeks from the time the drug is compounded.
Determining the correct beyond use date is an important step to ensure the patient is receiving a safe and effective medication. It can also help prevent waste to rotate stock and to have a good understanding of beyond use dates. There is nothing worse when someone doesn’t realize the storage requirements for a medication, such as refrigeration for eye drops, and an expensive medication needs to be thrown away. Just remember that once a medication is repackaged or compounded, it is assigned a beyond use date that is different (usually much sooner) from the original expiration date of the drug from the manufacturer.